1. Field of the Invention
The present invention relates to the technical field of liquid crystal displaying, and in particular to a backlight module.
2. The Related Arts
Liquid crystal display (LCD) has a variety of advantages, such as compact device size, low power consumption, and being free of radiation, and is thus widely used. Most of the LCDs that are currently available in the market are backlighting LCDs, which comprise a liquid crystal panel and a backlight module. The working principle of the liquid crystal panel is that liquid crystal molecules interposed between two parallel glass plates and a plurality of vertical and horizontal fine electrical wires is arranged between the two glass plates, whereby the liquid crystal molecules are controlled to change direction by application of electricity to refract light emitting from the backlight module for generating images. Since the liquid crystal panel itself does not emit light, light must be provided by the backlight module in order to generate images. Thus, the backlight module is one of the key components of an LCD. The backlight module can be classified as two types, namely side-edge backlight module and direct backlight module, according to the position where light gets incident. The direct backlight module arranges a light source, such as a cold cathode fluorescent lamp (CCFL) or a light-emitting diode (LED) at the back side of the liquid crystal panel to form a planar light source to directly provide lighting to the liquid crystal panel. The side-edge backlight module arranged an LED light bar of light source at an edge of a backboard that is located rearward of one side of the liquid crystal panel. The LED light bar emits light that enters a light guide plate through a light incident face of the light guide plate and is projected out through a light exit face after being reflected and diffused to thereby form a planar light source to be provided to the liquid crystal panel.
The side-edge backlight module comprises a backboard, a backlight source mounted on the backboard, a reflection plate, a light guide board, and optic films. To assemble the backlight module, the optic films, the light guide board, and the reflection plate must be properly positioned first before the optic films, the light guide board, and reflection plate are assembled inside the backboard. The conventional way of positioning is to riveting the optic films, the light guide board, and the reflection plate to the backboard with rivets. Such a positioning manner with riveting is generally hard to operate and needs high cost and may affect the backlighting to some extents.